1. Field of the Invention
The present invention relates to a fuel battery including a plurality of fuel battery cells coplanarly disposed.
2. Description of the Background Art
There are increasing expectations for practical use of fuel batteries as a novel power source in mobile electronic devices that underpin the information-driven society. The fuel batteries may be classified into different types depending on what electrolytic materials and fuels are used, such as phosphoric type, melting carbonate type, solid electrolyte type, solid polymer type, and direct alcohol type. Of these fuel batteries of different types, the direct alcohol fuel battery and the solid polymer type fuel battery, in which solid polymer ion-exchange membranes are used as an electrolytic material, generate power with high efficiency at normal temperatures. Therefore, it is currently discussed to launch these fuel batteries in the market as downsized power batteries to be mostly used in mobile electronic devices.
The direct alcohol fuel battery, in which alcohol or an alcohol aqueous solution is used as fuel, is structurally simplified and space-saving because it is relatively easy to design a storeroom for fuel as compared to other fuel batteries in which gases are used as fuel. Because of these advantages, the direct alcohol fuel battery has a particularly high potential as a downsized power cell useful in mobile electronic devices.
Conventionally, in fuel batteries, in order to feed mobile electronic devices with sufficient power that cannot be generated by one fuel battery cell, a plurality of fuel battery cells are electrically connected and combined with one another (fuel cell stack). An example thereof is a fuel battery including a plurality of fuel battery cells coplanarly disposed (hereinafter, also referred to as “planarly integrated fuel battery”) as disclosed in Japanese Patent Laying-Open No. 2004-079506 (Patent Document 1) and Japanese Patent Laying-Open No. 2006-093119 (Patent Document 2).
In order to use the planarly integrated fuel battery as a power source in different electronic devices such as mobile electronic devices, it is a very significant factor that the structure of the planarly integrated fuel battery can be designed in a flexible manner depending on various shapes and area dimensions of spaces limitedly available for the fuel battery in the electronic devices. Such a designing flexibility greatly contributes to improvements of production efficiency (simplified production process) and production costs of the fuel battery.
In general, such a conventional planarly integrated fuel battery described in Patent Documents 1 and 2 employs a structure in which a plurality of fuel battery cells share a fuel feeder. The fuel feeder is more specifically a unit where fuel to be supplied to the fuel battery cells is kept or distributed, and a liquid fuel storeroom 3 of Patent Document 3 and a bipolar plate 20 of Patent Document 2 corresponds to the fuel feeder. To apply the planarly integrated fuel battery thus structured to electronic devices having fuel battery housing spaces of different shapes and area dimensions, the integration of fuel battery cells requires more than just a simple design change. In fact, the whole fuel feeder and a system structure pertinent thereto need to be totally redesigned. Thus, it requires a complicated process to tailor the structure of the fuel battery through design changes for any electronic devices to which the fuel battery is applied, whereby production efficiency and production costs of the fuel battery are deteriorated.